1. Field of the Invention
The present invention relates to refrigeration mechanisms and, in particular, to such mechanisms that include electrically powered actuators.
2. Description of the Related Art
Modern refrigeration mechanisms, such as refrigerator/freezer units, have electrically powered actuators that perform a variety of functions. An example is an ice maker/dispenser. Normally, electrical motors perform functions such as operating valves to supply water to the ice maker, moving a rod or rack to eject ice that has been frozen from supplied water, and moving other structure to move, alter, or direct ice pieces to an ice delivery or dispensing chute.
In the case of an ice maker/dispenser, the user normally must manually push a button with a finger or move a glass or container against a lever to actuate the motors to dispense ice down the chute. In some models, the user can also manually push a button to select between ice cubes or crushed ice, and in some instances shaved ice. Normally, once actuated, the dispenser operates until the user releases the button or lever. In some cases, the dispenser motor continues until automatically stopped by a timer.
In either of these cases, there are situations where it may be desirable to automatically stop the dispensing motor even if the user has instructed it to continue. For example, if ice jams or clogs the ice dispensing chute, the user may continue to try to operate the dispensing motor. Ice would back up and potentially damage the system. Additionally, if a foreign object (a non-ice object) enters the chute, it would be advantageous to automatically detect the same and stop operation of the dispensing motor until the situation can be resolved.
Furthermore, maintenance is some times performed on the ice chute, or at or near the ice chute. It could be advantageous to disable the dispensing motor automatically. There are other reasons to stop moving parts, such as are obvious to those skilled in the art.
There can be other actuators in the form of motors, valves, fans, etc. that are electrically powered and may have moving parts or cause certain functions where it would be advantageous to have some sort of backup or failsafe automatic protection to disable or shut off the actuator for unwanted conditions.